X-ray devices such as handheld X-ray fluorescence (XRF) instruments are known as are various shields for such instruments. See U.S. Pat. Nos. 7,430,274; 7,375,359; 7,375,358; 6,965,118; and 7,671,350 as well as WO 00/37928 all incorporated herein by this reference. See also U.S. Published Application No. US-2008-0152079.
In recent years higher performance handheld XRF instruments have started to use larger active area silicon drift detectors (SDD's) in the range of 20 mm2 and greater. These larger area detectors are well suited for measuring low atomic number elements in the field due to their greater sensitivity; however, a drawback of using larger area SDD's is that the sealing windows required to maintain an evacuated chamber in the region of the silicon detector surface become more fragile with increased size. This drawback is exacerbated when a handheld XRF instrument is used in the field environment.
For example, when a handheld XRF instrument is used in mining or scrap metal applications, the measurement head must be placed in close proximity to test substances that may contain various types of debris that can pierce, or otherwise damage, the environmental sealing film and detector sealing window of the instrument. When this occurs, the sealing film can be replaced by the operator; however, the unit must be returned to the factory to have its detector replaced at considerable inconvenience and expense to the owner of the handheld XRF instrument. Accordingly, a solution that protects the detector sealing window while not deteriorating the performance of the handheld XRF instrument would be of great value to the users of these instruments.